Isaac allaed



uitenr tatrs @anni @frn ISAAC ALLARD, OEBE'LFAST, MAINE, AssIGNoR To HIMSELF AND `FRANK A. HOWARD,l on SAME PLAGE.

Leners Patent No. 80,583, aatedatgwt 4, 186s.

Inrnovrnsnr 1N s csrwfnmvnns.

To ALL WHOM '1T MAY coNcnRN:

Be it known thatI, ,IsAAc ALLARD, of Belfast, in the' county of Waldo, and State o f Maine, have inventeda, new and improved Screw-Driver; and IY do hereby' declare that the following is a'full, clear', and exact description thereoiwhich will enable those skilled in the art to make and use the same, reference being had `to the accompanying drawings, forming part of this specification.

This invention relatestoan improvement in screxv-drivers, whereby they are made much more''convenient and effective than those madein the ordinarymanner. 4And it consists in'making the shank of the screw-driver in a spiral form, by-,twistingv or otherwise, and operating it in a tube by a spiral spring, whereby 4the screw-driver is made self-revolving, in the manner hereinafter described.V .Y I f l The drawing represents a longitudinal section of a screwdriver made according topmy invention, Similar lettersl of reference indicate corresponding parts. A 'is the tube. l. B is the spiral shank.

C is a spiral spring, which is coiled around'the shank B. D is a follower, on the end-of the shank, which is made to t the tube, and which guides the shank as it is forced back and forth in thel tube. i l

E is a nut in the end of the tube through which 'the shank Vpasses, receiving therefrom a revolving motion, p

when passing in either'direction.

F is a spring-catch, by which the shank is held stationary, there being holes, g, in the Shank, which the end, t, of the catch enters, and prevents it from revolving'or moving up and down.

The spring vC is attached to the follower D, and to the nut E. As represented in the drawing, it is stretched i the thumb-pieces', and raisin-g the catch. v

Tooperate the screw-driver in 'driving wood-screws, insert the bit' n. in the slit of the screw, andV then press down the thumb-piece z'. This releases the shank, and the recoil of the spring will force the shank from the 4or elongated, and its tendency is to force the shank from the tube when the shank is released bypressing on tube, which revolvesat the same time, thus turning the screw into the wood, while the operator holds the handle p o'irmly in his hand. y

As seen inthe drawing, the shank is` held by the catch E, with ,the shank extended. The catch is inserted in the upper hole g.

` purpose specified.

The tool can lbe used in the first position named, or,` as seen, as a short stationary screw-driver', and in the latter case, with the shank extended, as a. long one.-

The advantages of this arrangement, whereby a self-revolving, and a long as well as a short screw-driver are secured, will at once be appreciated by all... i

I claiin as new, and desire to secure by Letters Patent- 1.' The tube A-,thc spiral shank B, and the spring C, whenthc same are constructed, arranged, and operated substantially as and for the purposes shown and described. l I

2. The springicatch F; in' combination with the spiral shank B and tube A, as herein describedfor the IsAAlc- ALLARD.

Witnesses:

TLMOTHY CHASE, A. D. CHASE. 

